The present invention relates to ink cartridges and inkjet printers.
Generally, color inkjet printers use a plurality of color inks. These printers may include a plurality of separate color ink cartridges that are independently replaceable. This structure allows the ink cartridges to be consumed completely, thus reducing costs.
In an inkjet printer that uses the separate ink cartridges, a cartridge accommodating portion accommodates the ink cartridges. Each ink cartridge must be accurately located at a predetermined position of the accommodating portion. Further, since each ink cartridge corresponds to a different color, the cartridges must be aligned in the accommodating portion in a predetermined order.
Conventionally, a positioning member divides the cartridge accommodating portion into a plurality of chambers. The positioning member positions each ink cartridge in the corresponding chamber, thus installing the cartridge in the printer.
However, the positioning member complicates the structure of the cartridge accommodating portion. Further, the cartridge accommodating portion must have a clearance for receiving the positioning member, in addition to the cartridge chambers. This enlarges the cartridge accommodating portion.
In an inkjet printer described in Japanese Unexamined Patent Publication No. 4-185355, an accommodating recess is formed as the cartridge accommodating portion. Convex and concave portions are formed in the inner wall of the recess. Matching convex and concave portions are formed in the outer wall of each ink cartridge. That is, when each cartridge is received in the recess, the convex and concave portions of the cartridge engage with those of the inner wall of the recess. In this manner, the cartridge is positioned in the recess.
However, in this case, the convex and concave portions must be formed with a high accuracy such that each ink cartridge is positioned in the recess accurately and reliably. The forming of the convex and concave portions is thus complicated. Particularly, machining of the inner wall of the recess is complicated such that production efficiency decreases.
In an inkjet printer described in Japanese Unexamined Patent Publication No. 61-41553, a plurality of head units are attached to a reciprocating carrier. Each head unit accommodates an ink container and includes an engaging projection and an engaging recess through which the head unit is connected to the adjacent head unit.
In this printer, each head unit accommodates a different color ink, and the head units must be aligned in a predetermined order. However, since these head units are identical, it is highly likely that the head units are aligned in an inaccurate order.